WASHINGTON (AP) — The House is plunging into a landmark impeachment week, with Democrats who once hoped to sway Republicans now facing the prospect of an ever-hardening partisan split over the historic question of removing President Donald Trump from office.

Lawmakers were getting their first look Monday night — behind closed doors — at the impeachment report from the House Intelligence Committee. The report, to be released Tuesday, is expected to forcefully make the Democrats’ case that Trump engaged in what Chairman Adam Schiff calls impeachable “wrongdoing and misconduct” in pressuring Ukraine to investigate Democrats and Joe Biden while he was withholding military aid.

For Republicans, the proceedings are simply a “hoax,” with Trump insisting he did nothing wrong and his GOP allies in line behind him. Late Monday, he tweeted his daily complaints about it all and then added a suggestive question: “Can we go to Supreme Court to stop?”

He didn’t elaborate.

It’s all boiling down to a historic test of political judgment in a case that is dividing Congress and the country.

Departing Monday for a NATO meeting in London, Trump also criticized the House for pushing forward with proceedings while he was heading overseas, a breach of political decorum that traditionally leaves partisan differences at the water’s edge.

He predicted Republicans would actually benefit from the entire impeachment effort against him, though “it’s a disgrace for our country.”

For the Democrats, House Speaker Nancy Pelosi faces a critical test of her leadership as she steers the process ahead after resisting the impeachment inquiry through the summer, warning it was too divisive for the country and required bipartisan support.

Speaking to reporters at the international climate conference in Madrid, Pelosi declined to engage with impeachment questions. “When we travel abroad, we don’t talk about the president in a negative way,” she said. “We save that for home.”

Possible articles of impeachment are focused on whether Trump abused his office as he pressed Ukrainian President Volodymyr Zelenskiy in a July 25 phone call to launch investigations into Trump’s political rivals. At the time, Trump was withholding $400 million in military aid, jeopardizing key support as Ukraine faced an aggressive Russia at its border.

The report from the Intelligence panel also was expected to include material the Democrats say suggests obstruction of Congress, based on Trump’s instructions for his administration to defy subpoenas for documents and testimony.

The next step comes Wednesday, when the Judiciary Committee gavels its own hearings open ahead of a possible impeachment vote by the full House by Christmas. That would presumably send the issue to the Senate for a trial in January.

The Democratic majority on the Intelligence Committee says its report, compiled after weeks of testimony from current and former diplomats and administration officials, will speak for itself in laying out the president’s actions toward Ukraine.

Ahead of the report’s public release, Republicans pre-empted with their own 123-page rebuttal.

In it, they claim there’s no evidence Trump pressured Zelenskiy. Instead, they say Democrats just want to undo the 2016 election. Republicans dismiss witness testimony of a shadow diplomacy being run by Trump lawyer Rudy Giuliani, and they rely on the president’s insistence that he was merely concerned about “corruption” in Ukraine — though the White House transcript of Trump’s phone call with Zelenskiy never mentions the word.